Barbossa is arguably his most famous screen role, even if it never nabbed him any awards. He has plenty of those, though, including the triple crown of Oscar, Emmy and Tony awards.

"Funnily enough I get a lot of fan mail; I find that interesting,” he tells Weekend.

"Now it's starting to come in from China and Slovenia and Russia. They're often very enthusiastic kids and teenagers. It's unbelievable how obsessive they are about all the nuances and details of the story.

"Some also seem to have a rather romantic, fantasy attraction about Barbossa.”

Captain Barbossa the sex symbol? Rush has a theory.

"I think they like that Barbossa has a sense of humour and there's something not creepy about the fact that he's so assured,” he says.

"Despite his vanity and how ruthless he is, it's that fantasy of if you could be a pirate then you get to live your own life. That's part of the historical reality. All these cretins got to go to sea, and they lived the high life but with no rule book. There's a subliminal impulse in that; everyone thinks 'wouldn't that be amazing?'”

The 65-year-old never dreamed the first Pirates film, The Curse of the Black Pearl, in 2003, would spawn more than a decade of work for him.

"I got shot at the end of the first film. I went 'Oh great, that was a really fun thing to do in my career and now I'll move on and do something else',” he says.

"Then Gore phoned me up and said actually we're going to do two and three and bring you back, mostly in three. I said 'But Gore, I'm dead'. He said 'Yeah, we'll use a bit of voodoo or movie magic. We need you back'.”

Rush relishes the chance to tap into his inner villain but it's Barbossa's evolution which has kept the notoriously picky actor interested.

"Over the course of the five films, he's gone from a spat out of the mouth of hell villain to a politician,” he says.

"There are so many dimensions (to him). I get to be narcissistic and ruthless. It's just fun to try and find the scale of that personality.”

In Dead Men Tell No Tales, the fifth instalment of the Pirates franchise filmed on the Gold Coast and in northern NSW, Barbossa has sold out and become a "corporate pirate'' with a fleet under his command.

"He's taken his eye off the ball and gone to seed a bit,” Rush says. "He's ridiculously wealthy but he doesn't know what to spend it on apart from decorating his wooden leg with gold and jewels.”

Rush is full of praise for his new co-star Javier Bardem, who plays Captain Salazar, the Spaniard who has spent more than 20 years plotting his revenge against pirates, and Sparrow in particular, from the crushing depths of Davey Jones' locker.

"Javier is so amazing to work with. His character emerges from 24 years under the ocean, so he's part human and part crustacean,” Rush says. "He's got squid ink coming out of his mouth but he does it with such charm.

"Barbossa has aged shockingly so, when we were doing our dialogue scenes together, circling around each other, it felt like foreplay between two crabs.”

It's unclear if this will be the final film in the Pirates franchise, which has grossed more than $3.7 billion worldwide.

"If it (the new film) does well, I don't know whether Johnny wants to continue or if Jerry (Bruckheimer, producer) thinks 'Hey, all five super blockbusters have all been very popular with families'. It may well be the end. There's a sense of completion,” Rush says. Either way, he has enjoyed his wild ride to the ends of the earth and beyond.

Pirates of the Caribbean: Dead Men Tell No Tales opens on Thursday. Genius airs Mondays at 8.30pm on the National Geographic Channel.